Abstract： Objective To evaluate the value of clinical application of the combination of CT and 99mTc-MDP bone scan in the follow-up monitoring of cancer recurrences of the breast cancer patients previously treated with both mastecomy and chemotherapy Methods 253 female breast cancer patients treated with mastectomy and chemotherapy within the past one year were enrolled in this study. All of them underwent CT,99mTc-MDP bone scan. calculation of the sensitivity, specialty, accuracy, were analyzed. Results There were 122 patients had the bone metastasis in 253 patients diagnosed breast cancer. the incidence rate was 48.2% . The thoracic part had the most incident of osseous metastasis(50.9%) ,then the vertebral body(41.8%) ,pelvis(25.4%),limbs bone (14. 5 %), skull and the other parts(9. 1%). The sensitivity, specialty, accuracy of 99mTc-MDP bone scan in determining osseuous metastasis were 93.2% 、90. 7% 、91.3% respectively;The sensitivity, specialty,accuracy of CT in the detection of cancer recurrence were 58. 2% 、87.8% 、73.5% respectively in CT scan.When combining 99mTc-MDP bone scan with CT scan,they were 93.4% 、91.6% 、92.5% respectively. Conclusion The incidence rate of osseous metastasis is very high for the breast cancer patients, and the incidence of the osseous metastasis has definite rules and features. the combination of CT and 99mTc-MDP in the follow-up studies of the breast cancer patients previously treated with both mastectomy and chemotherapy can obtain the higher sensitivity, specialty and accuracy, making a significant contribution to the value of clinical application.